Golf club shaft and golf club

ABSTRACT

A golf club shaft is formed by curing wound fiber-containing prepregs and has a tip side and a butt side. In an embodiment, the prepregs include pitch-based carbon fiber-containing prepregs with a low elastic modulus, which are wound on the tip side, and polyacrylonitrile (PAN) based carbon fiber-containing prepregs, which are wound in an outermost layer on the tip side. In another embodiment, the prepregs include low-elasticity carbon fiber-containing prepregs wound on the tip side, and high-elasticity carbon fiber-containing prepregs wound on the butt side. In yet another embodiment, the prepregs include low-elasticity carbon-containing prepregs, which are wound on the butt side, and high elasticity carbon-containing prepregs, which are wound on the tip side.

CROSS-REFERENCE TO RELATED APPLICATION

This Application claims priorities from Japanese Patent Application No. 2012-075703 filed Mar. 29, 2012, Japanese Patent Application No. 2012-075704 filed Mar. 29, 2012, and Japanese Patent Application No. 2012-075705 filed Mar. 29, 2012, which are incorporated herein by reference in their entirety.

BACKGROUND OF THE INVENTION

The present invention relates to a golf club shaft, more particularly to a fiber reinforced resin-made golf club shaft, and to a golf club including the fiber reinforced resin-made golf club shaft.

As shown in FIG. 2, a golf club 1 includes a shaft 3, which is mounted to a head 2. A grip 4 is provided on a trailing edge side (i.e., butt side) of the shaft 3. As shown in FIG. 3, in mounting the shaft 3 to the head 2, an epoxy-based adhesive 5 or the like is applied to a leading edge of the shaft 3, the shaft 3 is inserted into a hozel hole 6 of the head 2 and then the adhesive 5 is cured. FIGS. 2 and 3 illustrate a wood type golf club, such as a driver. A shaft is mounted to a head in iron type, utility type, and putter type golf clubs, similarly to the wood type golf club illustrated in FIGS. 2 and 3.

Golf club shafts are broadly classified into steel shafts and carbon shafts. Among them, carbon shafts have been widely used from the viewpoint of their light weight and high design flexibility.

Carbon shafts are made of fiber reinforced resins, which include carbon fibers as their main fiber. For a method for manufacturing such a carbon shaft, Japanese Patent Application Publication No. 2010-259694 discloses a sheet winding method. In this manufacturing method, sheet-like prepregs are wound around a mandrel (a cored bar), wrapping tapes are wound therearound, and then the prepregs are cured by heating to manufacture a carbon shaft.

Carbon fibers include polyacrylonitrile (PAN)-based carbon fibers, which are made of PAN as their main raw material, and pitch-based carbon fibers, which are made of pitches as their main raw material. The PAN-based carbon fibers and the pitch-based carbon fibers respectively various grades of different elastic moduli. Pitch-based carbon fibers of wide elastic moduli in tension ranging from about 59 GPa to 935 GPa, which are achieved by adjusting the thermal treatment (baking) temperature, have been conventionally provided.

Deformation characteristics of carbon shafts vary according to the elastic modulus of carbon fibers. For example, when carbon fibers of low elastic modulus are arranged on the leading edge side (i.e., tip side) of the shaft, the tip side of the shaft may be easily deformed.

The momentum of a golf club becomes greater as the leading edge side of the golf club, to which the head is fixed, becomes heavier. With this configuration of golf clubs, a high initial velocity may be imparted to a ball when it is shot to achieve a longer carry. In the case of players of less power, not only may the carry be short but also the shot ball may not fly high because of a low head speed.

Japanese Patent Application Publication No. 09-253254 discloses a golf club intended to increase the head speed around an impact zone when a player of less power swings a golf club shaft by allowing the tip side of a shaft to be easily relatively deformed due to an increased thickness of prepregs wound on the butt side of the shaft.

SUMMARY OF THE INVENTION

In arranging carbon fibers having a low elastic modulus on the tip side of a shaft to impart a low elasticity to the tip side of the shaft, the strength of the shaft may become low if pitch-based carbon fibers are arranged on an outer periphery side because the tensile strength of pitch-based carbon fibers is lower than that of PAN-based carbon fibers. In addition, if pitch-based carbon fibers having a fiber diameter larger than that of PAN-based carbon fibers are used, the surface of the fibers may become hairy when the shaft is ground to adjust the diameter of the shaft, which may result in degraded appearance of the shaft.

The purpose of the present invention is to provide a shaft in which carbon fibers having a low elastic modulus is arranged on its tip side and the tip side thereof having a high strength and a satisfactory appearance, and a golf club including the shaft.

In a golf club having a shaft in which the tip side thereof is allowed to be easily deformed by additionally winding prepregs on its butt side, the weight of the shaft may increase by the weight increased on the butt side. Therefore, it becomes less easy for a player of less power to swing a golf club with such a shaft.

Another purpose of the present invention is to provide a golf club shaft in which the tip side thereof is allowed to be easily deformed without needlessly increasing the weight of the shaft and a golf club having the golf club shaft.

In addition, in a golf club having a shaft in which the tip side thereof is allowed to be easily deformed by additionally winding prepregs on its butt side, if an advanced player or the like who can hit the ball at a high head speed swings such a golf club, the golf club may be deformed with the degree of deformation concentrated on the leading edge side thereof. Therefore, the portion with the maximum deformation may differ according to a slight change in the timing and the speed of the swing (for example, the timing of turning the wrist). As a result, the courses of hit balls may not be stabile.

Yet another purpose of the present invention is to provide a golf club shaft which is enabled to be entirely and uniformly deformed instead of being deformed concentrated on its tip side and a golf club having the golf club shaft.

According to an aspect of the present invention, a golf club shaft is formed by curing wound fiber-containing prepregs and has a tip side and a butt side, the wound fiber-containing prepregs including: pitch-based carbon fiber-containing prepregs with a low elastic modulus, which are wound on the tip side; and polyacrylonitrile (PAN)-based carbon fiber-containing prepregs, which are wound in an outermost layer on the tip side.

The wound fiber-containing prepregs may further include polyacrylonitrile-based carbon fiber-containing prepregs extending continuously from the tip side to the butt side of the golf club shaft.

According to the golf club shaft of this aspect, in which pitch-based carbon fibers with a low elastic modulus are arranged on the tip side of the shaft, the tip side of the shaft is easily deformed. Golf clubs in which the tip side of the shaft is easily deformed tend to be preferred by players with low head speed.

In the golf club shaft of this aspect, PAN-based carbon fiber-containing prepregs are wound in the outermost layer on the tip side. Because the tensile strength of the PAN-based carbon fibers constituting the PAN-based carbon fiber-containing prepregs is high, the strength of the shaft is high on the tip side thereof. Furthermore, because the fiber diameter of the PAN-based carbon fiber is small, polished portions may not become hairy. As a result, a satisfactory appearance of the golf club can be maintained.

In another aspect of the present invention, a golf club shaft is formed by curing wound fiber-containing prepregs and has a tip side and a butt side, the wound fiber-containing prepregs including: low-elasticity carbon fiber-containing prepregs wound on the tip side; and high-elasticity carbon fiber-containing prepregs wound on the butt side.

The wound fiber-containing prepregs may further include: main prepregs extending continuously from the tip side to the butt side of the golf club shaft and including polyacrylonitrile-based carbon fibers which are oriented in a straight direction with respect to a longitudinal direction of the shaft; and bias prepregs extending continuously from the tip side to the butt side of the golf club shaft and including polyacrylonitrile-based carbon fibers which are oriented in a bias direction with respect to the longitudinal direction of the shaft.

The low-elasticity carbon fibers may have a tensile elastic modulus of 5 to 20 ton·f/mm². The high-elasticity carbon fibers may have a tensile elastic modulus of 40 to 80 ton·f/mm². The main prepregs may have a tensile elastic modulus of 10 to 80 ton·f/mm². The bias prepregs may have a tensile elastic modulus of 40 to 46 ton·f/mm².

The high-elasticity carbon fiber -containing prepregs may have a length from 15 to 45% of the entire length of the shaft on the butt side. The low-elasticity carbon fiber-containing prepregs may have a length from 5 to 45% of the entire length of the shaft on the tip side.

According to the golf club shaft of this aspect, low-elasticity carbon-containing prepregs are arranged on the tip side and high elasticity carbon-containing prepregs are arranged on the butt side. Accordingly, the tip side is allowed to be easily deformed without allowing the thickness of the prepregs wound on the butt side to become excessively great. In the golf club shaft, because the thickness of the wound prepregs is not excessively great, the weight of the shaft may also be achieved.

In yet another aspect of the present invention, a golf club shaft is formed by curing wound fiber-containing prepregs and has a tip side and a butt side, the wound fiber-containing prepregs including: low-elasticity carbon-containing prepregs wound on the butt side; and high elasticity carbon-containing prepregs wound on the tip side.

The wound fiber-containing prepregs may further include: main prepregs extending continuously from the tip side to the butt side of the golf club shaft and including polyacrylonitrile-based carbon fibers which are oriented in a straight direction with respect to a longitudinal direction of the shaft; and bias prepregs extending continuously from the tip side to the butt side of the golf club shaft and including polyacrylonitrile-based carbon fibers which are oriented in a bias direction with respect to the longitudinal direction of the shaft.

The low-elasticity carbon fibers may have a tensile elastic modulus of 5 to 20 ton·f/mm². The high-elasticity carbon fibers may have a tensile elastic modulus of 10 to 80 ton·f/mm². The main prepregs may have a tensile elastic modulus of 10 to 80 ton·f/mm². The bias prepregs may have a tensile elastic modulus of 40 to 60 ton·f/mm².

The high-elasticity carbon fiber-containing prepregs may have a length from 5 to 45% of the entire length of the shaft on the tip side. The low-elasticity carbon fiber-containing prepregs may have a length from 15 to 45% of the entire length of the shaft on the butt side.

According to the golf club shaft of this aspect, in which the diameter on the tip side is smaller than that on the butt side, low-elasticity carbon fibers are arranged on the butt side and high-elasticity carbon fibers are arranged on the tip side thereof, and thereby when an advanced player or the like who can hit the ball at a high head speed swings the golf club, the deformation of the shaft may not be concentrated on the tip side and the entire shaft is allowed to deform. With this configuration, great difference of the courses of the hit balls can be prevented regardless of any difference in the timings of swings, which results in stabilized courses of hit balls.

According to still yet another aspect of the present invention, a golf club includes the golf club shaft according to any of the above-described aspects and a head.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view illustrating an example of various types of prepregs for manufacturing the golf club shaft according to the present invention.

FIG. 2 is a perspective view illustrating an example of the golf club according to the present invention.

FIG. 3 is a perspective view illustrating an example of a method for mounting a head to the golf club shaft according to the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinbelow, an embodiment of a golf club shaft and a golf club according to the present invention will be described.

FIG. 1 is a development illustrating various types of prepregs for manufacturing an embodiment of the golf club shaft according to the present invention. In this manufacturing method, a mandrel 10 and prepregs 11 to 19 are used. The axial line of the mandrel 10 is a straight line. The shape of the cross section perpendicular to the shaft axial center line of the mandrel 10 is circular. The mandrel 10 includes a taper such that the tip side (head side) is narrow and the butt side (grip side) is thick. However, the mandrel 10 may include a portion having a regular diameter, which has a partially constant diameter.

Preferably, after applying a mold release agent on a surface of the mandrel 10, sheet-like prepregs 11 to 19 are serially wound.

The prepregs 11 to 19 include carbon fibers and a matrix resin. The carbon fiber for the prepreg 11 is a pitch-based low-elastic modulus carbon fiber. The carbon fibers for the prepregs 12, 13, 15 to 17, and 19 are PAN-based carbon fibers. The carbon fibers for the prepregs 14 and 18 may be either PAN-based carbon fibers or pitch-based carbon fibers.

In this embodiment, in the prepregs 11 and 14 to 19, the carbon fibers are oriented in a straight direction, i.e., in a direction parallel to the longitudinal direction of the shaft. The fiber orientation angle of the straight direction is 0° with respect to the shaft central axis, but the present invention is not limited to this. The fiber orientation angle of the straight direction may be in a range of 0±3°. In the prepreg 12, the carbon fibers are oriented in a bias direction, i.e., in a direction obliquely crossing the longitudinal direction of the shaft) by +45°. In the prepreg 13, the carbon fibers are oriented in the bias direction of by −45°. Alternatively, the carbon fibers for the prepreg 12 may be oriented in the bias direction of −45° and the carbon fibers for the prepreg 13 may be oriented in the bias direction of +45°. The angle of bias for the bias direction is not limited to 45° and may be in the range of 30 to 60°.

The prepregs 12, 13, and 15 to 17 respectively have a length extending in the entire length of the shaft. The prepregs 11, 18, and 19 respectively have a length of 5 to 45%, particularly preferably 8 to 30%, of the entire length of the shaft so that they are arranged on the tip side of the shaft only. The prepreg 14 is arranged on the butt side only. The length of the prepreg 14 in the longitudinal direction of the shaft is preferably 15 to 45%, more preferably 20 to 40%, and particularly preferably 25 to 35%, of the shaft.

The prepregs 15 to 17 respectively have a width large enough to be wound around the mandrel 10 on the outer periphery thereof by 1 wrap only. The prepregs 11 to 14 and 18 respectively have a width large enough to be wound around the mandrel 10 on the outer periphery thereof by a plurality of wraps, e.g., about 2 to 5 wraps. The prepreg 19 has a width large enough to be wound around the mandrel 10 on the outer periphery thereof by about 1 to 10 wraps.

The thickness of the prepregs 12 and 13 is preferably 0.125 mm or less, and particularly about 0.05 to 0.1 mm. The thickness of the prepregs 15 to 17 is preferably 0.125 mm or less, and particularly about 0.05 to 0.1 mm. The thickness of the prepreg 14 is preferably 0.125 mm or less, and particularly about 0.05 to 0.1 mm. The thickness of the prepregs 11, 18, and 19 is preferably 0.125 mm or less, and particularly about 0.05 to 0.1 mm.

The suitable ratio of the fiber in each of the prepregs 11 to 19 is FAW 10 to 150g/m², and particularly preferably 20 to 125 g/m². For the resin for the prepregs, epoxy resins and the like are suitable.

The tensile elastic modulus of the PAN-based carbon fibers included in the prepregs is preferably about 10 to 80 ton·f/mm² (about 98 to 784 GPa), particularly preferably 24 to 40 ton·f/mm² (about 235 to 392 GPa) in the straight direction and preferably high about 40 ton·f/mm² (about 392 GPa) or higher, particularly preferably 40 to 46 ton·f/mm² (about 392 to 451 GPa), in the bias direction. The fiber diameter of the PAN-based carbon fibers is preferably about 5 to 7 μm. Note that 1 GPa=0.098 ton·f/mm².

The tensile elastic modulus of the pitch-based carbon fibers is preferably 5 to 20 ton·f/mm² (about 49 to 196 GPa). The fiber diameter of the pitch-based carbon fibers is preferably 10 to 13 μm and particularly preferably 11 to 12 μm.

In winding the prepregs 11 to 19 around the mandrel 10, the prepregs 11 to 19 may be wound sheet by sheet, or alternatively, the prepregs may be wound after some of them are attached to one another. For example, the prepregs 15 and 16, or the prepregs 16 and 17 may be attached. The operation for winding the prepregs 11 to 19 around the mandrel 10 may be carried out by operators, or alternatively, can be carried out with a winder (rolling machine). After winding the prepregs 11 to 19 around the mandrel 10, a step for winding a wrapping tape is carried out. Although not illustrated in the drawing, the wrapping tape is wound in a helical manner.

After the winding step, a curing step is carried out by heating the prepregs to cure the matrix resin included in the prepregs.

After the curing step, the mandrel 10 and the wrapping tape are removed. Thus, a cured tube-like body (element tube) is obtained. Both ends of the elemental tube are cut as necessary, the tube is polished, and thus the golf club shaft 3 (FIG. 2) is obtained. As shown in FIG. 2, by mounting the head 2 and the grip 4 to the golf club shaft 3, the golf club 1 is obtained. As shown in FIG. 3, in mounting the head 2, the adhesive 5, which is an epoxy-based adhesive or the like, is applied to the golf club shaft 3 on its leading edge. Then the shaft 3 is inserted into a hozel hole 6 of the head 2 and then the adhesive 5 is cured.

In this golf club, the pitch-based carbon fiber-containing prepregs 11 and 18 having a low elastic modulus, are arranged on the tip side of the shaft and the PAN-based carbon fiber-containing prepreg 19 is arranged on the outer periphery side. Thus, the tip side is allowed to be easily deformed. Because the elastic modulus of the carbon fibers for the prepregs 11 and 18 arranged on the tip side only is low, the rigidity on the tip side would not become excessively high even if the thickness of the tip side is increased. By increasing the thickness on the tip side, the shearing strength on the tip side can be increased to a high level.

In addition, because the outer periphery side on the tip side includes the PAN-based carbon fiber-containing prepregs and the elastic modulus of the PAN-based carbon fibers is high, the strength on the tip side of the shaft is high. Because the fiber diameter of the PAN-based carbon fibers is small, the shaft would not become hairy even when it is polished. As a result, a satisfactory appearance of the shaft can be maintained.

The example of lamination of prepregs illustrated in FIG. 1 is a mere example of the present invention. More specifically, lamination examples other than that illustrated in FIG. 1 can be employed. For example, in FIG. 1, prepregs of which the direction of carbon fibers is in a hoop direction (peripheral direction) may be provided between the prepregs 15 and 16 or between the prepregs 16 and 17 of which the direction of carbon fibers is in the straight direction.

The total quantity of the bias prepregs 12 and 13 may be 4 to 6. 3 to 5 pieces of prepregs having fibers in the straight direction, 2, 4, or 6 pieces of prepregs having fibers in the bias direction, and 1 to 3 prepregs having fibers in the hoop direction are usually and preferably laminated.

As described above, carbon fibers only are included in the prepregs. However, other fibers such as glass fibers, silicon carbide fibers, alumina fibers, aromatic polyamide fibers, or boron fibers may be further combined.

The shaft according to this embodiment can be applied to various types of golf clubs, such as wood type, utility type, iron type, or patter type golf clubs.

Now, a second embodiment of the present invention will be described. Descriptions of its configurations and steps similar to those of the first embodiment described above will not be repeated here.

In this embodiment, the carbon fibers for the prepregs 11 and 18 may be either PAN-based carbon fibers or pitch-based low-elastic modulus carbon fibers. The carbon fibers for the prepregs 12 to 17 are PAN-based carbon fibers. The carbon fibers for the prepregs 19 may be either PAN-based carbon fibers or pitch-based carbon fibers, preferably may be PAN-based carbon fibers. The carbon fiber for the prepreg 14 is a PAN-based high-elastic modulus carbon fiber.

In this embodiment, for the elastic modulus of the PAN-based carbon fibers included in the prepregs, for the main prepregs 15 to 17 having the fibers in the straight direction, 10 to 80 ton·f/mm² (about 98 to 784 GPa), particularly preferably 24 to 40 ton·f/mm² (about 235 to 392 GPa) is preferable. For the carbon fibers for the bias prepregs 12 and 13, 40 ton·f/mm² (about 392 GPa) or higher, particularly preferably 40 to 46 ton·f/mm² (about 392 to 451 GPa) is preferable. For the elastic modulus of the PAN-based carbon fibers included in the prepreg 14 provided on the butt side, a high elasticity of about 40 to 80 ton·f/mm², particularly preferably 40 to 46 ton·f/mm² (about 392 to 451 GPa) is preferable.

For the elastic modulus of the carbon fibers included in the prepregs 11, 18, and 19, a low elasticity of about 5 to 20 ton·f/mm² (about 49 to 196 GPa) is preferable. Note that 1 GPa=0.098 ton·f/mm².

In this golf club, carbon fibers having a high elastic modulus are used for the prepreg 14 provided on the butt side and carbon fibers having a low elastic modulus are used for the prepregs 11, 18, and 19 provided on the tip side of the shaft. With this configuration, the shaft is easily deformed on the tip side. Because the carbon fibers for the prepregs 11, 18, and 19 arranged on the tip side only have a low elastic modulus, the rigidity on the tip side may not become excessively high even if the thickness on the tip side is increased. By increasing the thickness on the tip side, the shearing strength on the tip side can be increased to a high level. In addition, because the elastic modulus of the carbon fibers of the prepreg 14 arranged on the butt side is high, the elasticity of the shaft on the butt side can be high without needlessly increasing the thickness of the sound the prepreg 14. Furthermore, the weight of the shaft can be prevented from increasing. As a result, it is enabled for powerless players to swing the golf club at a high swing speed.

The shaft according to this embodiment is applied to wood type golf clubs such as a drive, spoon, and the like, utility type golf clubs, iron type golf clubs, or the like, and is particularly suitable when applied to wood type or utility type golf clubs having a long shaft.

Now, a third embodiment of the present invention will be described. Descriptions of its configurations and steps similar to those of the first embodiment described above will not be repeated here.

In this embodiment, the carbon fibers for the prepregs 11 to 13 and 15 to 19 have an elasticity higher than that of the carbon fibers for the prepreg 14. The carbon fibers for the prepreg 14 are low elasticity carbon fibers.

The prepregs 12, 13, and 15 to 17 respectively have a length extending in the entire length of the shaft. The prepregs 11, 18, and 19 respectively have a length of about 5 to 45%, particularly preferably about 8 to 30%, of the entire length of the shaft so that they are arranged on the tip side of the shaft only. The prepreg 19 is wound on the outermost periphery on the tip side and has a length long enough to reach a portion for insertion into the hozel hole of the shaft or to reach the insertion portion and the vicinity thereof. Note that the term “vicinity” refers to a range of 0 to 400 mm, particularly 50 to 200 mm, from an upper end of the hozel. The prepreg 19 may be arranged 500 mm, particularly preferably 300 mm, away from the leading edge of the shaft. The prepreg 14 is arranged on the butt side only. The length of the prepreg 14 in the longitudinal direction of the shaft is preferably 15 to 45%, more preferably 20 to 40%, and particularly preferably 25 to 35%, of the shaft.

The thickness of the prepregs 12 and 13 is preferably 0.125 mm or less, and particularly about 0.05 to 0.1 mm. The thickness of the prepregs 15 to 17 is preferably 0.125 mm or less, and particularly about 0.05 to 0.1 mm. The thickness of the prepreg 14 is preferably 0.125 mm or less, and particularly about 0.05 to 0.1 mm. The thickness of the prepregs 11 and 18 is preferably 0.125 mm or less, and particularly about 0.05 to 0.1 mm. The thickness of the prepreg 19 is preferably 0.125 mm or less, and particularly about 0.05 to 0.1 mm.

The tensile elastic modulus of the high elasticity carbon fibers included in the prepregs is preferably about 10 to 80 ton·f/mm² (about 98 to 784 GPa), particularly preferably 24 to 40 ton·f/mm² (about 235 to 392 GPa) in the straight direction and preferably high about 40 ton·f/mm² (about 392 GPa) or higher, particularly preferably 40 to 46 ton·f/mm² (about 392 to 451 GPa), in the bias direction. Note that 1 GPa=0.098 ton·f/mm².

The elastic modulus of the carbon fibers included in the prepreg 14 arranged on the butt side is preferably low about 5 to 20 ton·f/mm² (about 49 to 196 GPa), particularly preferably about 10 to 15 ton·f/mm² (about 98 to 147 GPa).

Pitch-based carbon fibers are suitable for the low elasticity carbon fibers used for the prepreg 14. PAN-based carbon fibers are suitable for the carbon fibers for other prepregs.

In this golf club, the elastic modulus of the carbon fibers for the prepreg 14 arranged on the butt side is low and the elastic modulus of the carbon fibers for the prepregs 11, 18, and 19 arranged on the tip side of the shaft is high. Because the diameter on the tip side is smaller than that on the butt side and low-elasticity carbon fibers are arranged on the butt side and high-elasticity carbon fibers are arranged on the tip side thereof, when an advanced player or the like who can hit the ball at a high head speed swings the golf club, the deformation of the shaft may not be concentrated on the tip side and the entire shaft is allowed to deform. With this configuration, great difference of the courses of the hit balls can be prevented regardless of any difference in the timings of swings, and as a result, stabilized courses of hit balls are achieved.

The shaft according to this embodiment is applied to wood type golf clubs such as a drive, spoon, and the like, utility type golf clubs, iron type golf clubs, or the like, and is particularly suitable when applied to wood type or utility type golf clubs having a long shaft. 

What is claimed is:
 1. A golf club shaft having a tip side and a butt side and being formed by curing wound fiber-containing prepregs, the wound fiber-containing prepregs comprising: pitch-based carbon fiber-containing prepregs with a low elastic modulus, which are wound on the tip side; and polyacrylonitrile-based carbon fiber-containing prepregs, which are wound in an outermost layer on the tip side.
 2. The shaft according to claim 1, wherein the wound fiber-containing prepregs further comprises polyacrylonitrile-based carbon fiber-containing prepregs extending continuously from the tip side to the butt side of the golf club shaft.
 3. A golf club comprising: the golf club shaft according to claim 1; and a head.
 4. A golf club shaft having a tip side and a butt side and being formed by curing wound fiber-containing prepregs, the wound fiber-containing prepregs comprising: low-elasticity carbon fiber-containing prepregs wound on the tip side; and high-elasticity carbon fiber-containing prepregs wound on the butt side.
 5. The shaft according to claim 4, wherein the wound fiber-containing prepregs further comprises: main prepregs extending continuously from the tip side to the butt side of the golf club shaft and comprising polyacrylonitrile-based carbon fibers which are oriented in a strait direction with respect to a longitudinal direction of the shaft; and bias prepregs extending continuously from the tip side to the butt side of the golf club shaft and comprising polyacrylonitrile-based carbon fibers which are oriented in a bias direction with respect to the longitudinal direction of the shaft.
 6. The golf club shaft according to claim 5, wherein the low-elasticity carbon fibers have a tensile elastic modulus of 5 to 20 ton·f/mm², the high-elasticity carbon fibers have a tensile elastic modulus of 40 to 80 ton·f/mm², the main prepregs have a tensile elastic modulus of 10 to 80 ton·f/mm², and the bias prepregs have a tensile elastic modulus of 40 to 46 ton·f/mm².
 7. The golf club shaft according to claim 4, wherein the high-elasticity carbon fiber-containing prepregs have a length from 15 to 45% of the entire length of the shaft on the butt side.
 8. The golf club shaft according to claim 4, wherein the low-elasticity carbon fiber-containing prepregs have a length from 5 to 45% of the entire length of the shaft on the tip side.
 9. A golf club comprising: the golf club shaft according to claim 4; and a head.
 10. A golf club shaft having a tip side and a butt side and being formed by curing wound fiber-containing prepregs, the wound fiber-containing prepregs comprising: low-elasticity carbon-containing prepregs wound on the butt side; and high elasticity carbon-containing prepregs wound on the tip side.
 11. The golf club shaft according to claim 10, wherein the wound fiber-containing prepregs further comprise: main prepregs extending continuously from the tip side to the butt side of the golf club shaft and comprising polyacrylonitrile-based carbon fibers which are oriented in a straight direction with respect to a longitudinal direction of the shaft; and bias prepregs extending continuously from the tip side to the butt side of the golf club shaft and comprising polyacrylonitrile-based carbon fibers which are oriented in a bias direction with respect to the longitudinal direction of the shaft.
 12. The golf club shaft according to claim 11, wherein the low-elasticity carbon fibers have a tensile elastic modulus of 5 to 20 ton·f/mm², the high-elasticity carbon fibers have a tensile elastic modulus of 10 to 80 ton·f/mm², the main prepregs have a tensile elastic modulus of 10 to 80 ton·f/mm², and the bias prepregs have a tensile elastic modulus of 40 to 60 ton·f/mm².
 13. The golf club shaft according to claim 10, wherein the high-elasticity carbon fiber-containing prepregs have a length from 5 to 45% of the entire length of the shaft on the tip side.
 14. The golf club shaft according to claim 10, wherein the low-elasticity carbon fiber-containing prepregs have a length from 15 to 45% of the entire length of the shaft on the butt side.
 15. A golf club comprising: the golf club shaft according to claim 10; and a head. 